San Francisco's sky-high housing market - try $3,200 per month for a small apartment - comes with an extra irritant. Short-stay rentals offered through websites such as Airbnb and VRBO - are turning couch-surfing into a major industry filled with abuses and few rules.

That's the backdrop to proposed legislation from Supervisor David Chiu. His effort knocks the edges off the problem, but introduces other aspects that could prove troublesome. Lawmakers should move cautiously in tinkering with the issue of overnight rentals in a crowded, high-cost city.

Just as shared-ride services have changed the taxi business, so have online sites that connect visitors to units scattered across the city. The trend has taken hold across the country, making San Francisco's first swipe at the issue possibly precedent setting.

The legislation aims to bring order to the chaotic business. To qualify as a short-stay host, a resident would need to live in the unit 75 percent of the time, a threshold that bars absentee owners from turning a dwelling into a hotel room.

A host would need to sign up on a city registry, obtain liability insurance, and pay a 14 percent hotel tax on overnight stays. These changes would bring a shadowy industry rumored to include thousands of units into the open and require payment of a bed tax on a par with conventional hotels. Also, tenants in rent-controlled units couldn't profit by charging more than they presently pay.

But there are significant problems with Chiu's solution. By changing city law to allow brief rentals, the law would limit landlords from controlling who uses their property. Property owners could still bar the sublets if lease or rental agreements forbid it, but that legal course can take undue time. It's a key reason behind tenant group support for the measure.

The idea of a city registry comes with doubts about fees, enforcement and bureaucracy. Many short-stay hosts may dodge this requirement, leaving San Francisco no better off.

The winners, in short, are tenants who will receive the right to rent now not allowed under zoning laws. Landlords will need to give ground in limiting who can use their property.

Chiu argues that his plan is better than the ungoverned present world. The hosting websites are exploiting the confusion and lack of rules to further their business. Landlords also are quick to evict a tenant who rents a spare bedroom or the entire unit.

His plan rewards good behavior such as limited rentals offered by people who may need extra income or are filling empty beds when the hosts aren't around. It also recognizes the obvious: a semi-underground part of the travel industry is here to stay and can't be chased away. That's one reason Airbnb cites in offering general support for the proposal.

But a better balance needs to be struck. In a city where tenant activists and eviction horror stories are plentiful, it's not hard to see where politics is pushing the debate. The concerns of landlords and neighbors need greater consideration than Chiu's plan is offering.